The present invention relates to a swing suppressing device mounted on an industrial vehicle.
For example, in an industrial vehicle such as a forklift, in order to enhance vehicle stability upon traveling, an axle for supporting rear wheels is mounted swingably to a vehicle body. However, when the vehicle turns, in the case where the angular motion of the above-described axle is kept free, in some cases, the vehicle is so tilted that the traveling stability in turn would be degraded.
Accordingly, there is proposed a swing controlling device for controlling a swing motion of the axle within a suitable range as shown in Japanese Patent Application Laid-open No. 10-287116 or the like.
This swing controlling device is provided with a swing suppressing mechanism for suppressing (locking) the swing of the axle that may move up and down. This mechanism is controlled by a lateral acceleration (lateral G) and an idle rotation of the front wheels. In the above-described swing suppressing mechanism (swing suppressing device), a damper is generally interposed between the axle and the chassis so that the expansion and retraction of the damper may be locked or released.
If this swing controlling device is used, in the case where the lateral G is equal to or more than a predetermined level, the swing of the axle is locked to thereby suppress the tilt of the chassis and even in this case, if the front wheels are rotated in an idle manner, the swing lock of the axle is released to make it possible to escape from the idle rotation condition of the front wheels. For this reason, it is possible to perform the swing control of the axle at an optimum timing to thereby considerably enhance the traveling stability.
By the way, there are a variety of industrial vehicles having the axle that may swing and also a variety of different forms therefor. For example, in some cases, an upper space above the rear axle, i.e., a space between an upper portion of the axle and a battery or a frame of the chassis is small. In this case, it is impossible to directly interposed the above-described damper which forms the swing suppressing mechanism (swing suppressing device), between the chassis and the axle. For this reason, for the industrial vehicles having the small space above the rear axle, it is difficult to arrange the above-described swing suppressing device.
In view of the foregoing defects inherent in the conventional cases, an object of the present invention is to provide a swing suppressing device that may readily be arranged even in the case where the space above the swingable axle is small.
In order to attain this and other objects, according to the present invention there is provided a swing suppressing device for suppressing a swing motion of an axle that is mounted swingably up and down on a vehicle body of an industrial vehicle, said swing suppressing device comprising: a damper that may switch over between an expansion/retraction enable condition and an expansion/retraction disable condition; and a link mechanism for coupling said damper and said axle with each other, said damper being disposed with its expansion/retraction direction being set toward a substantially horizontal direction between said vehicle body and said axle, and with its one end being connected to said vehicle body and the other end being connected to said axle through said link mechanism, and said link mechanism converting the swing motion in the up-and-down direction of said axle to the motion in the substantially horizontal direction and transmitting it to said damper.